Automatic firearm



3 931 c. PFEIFFER AUTOMATIC FIREARM Original Filed Nov. 15, 1929 4 Sheets-Sheet l May 5, 1931. c. PFEIFFER AUTOMATIC FIREARM Original Filed Nov. 4 Sheets- Sheet 2 A y MM r. 0 Z w A 5] Vfi m May 5, 1931. c. PFEIFFER AUTOMATIC FIREARM 4 Sheets-Sheet 5 Original Filed Nov. 15, 1929 Jul sitar "it? [Zvrfstfan Pfezffer Patented May 5, 1931 UNITED STATES PATENT OFFICE CHRISTIAN PFEIFFER, OF HARTFORD, CONNECTICUT, ASSIGNOR CO'LTS PATENT FIRE ARMS MANUFACTURING 00., OF HARTFORD, CONNECTICUT, A CORPORATION OF CONNECTICUT AUTOMATIC FIREARM Application filed November 15, 1929, Serial No. 407,522. Renewed December 31, 1930.

The present invention is particularly applicable to a machine gun constructed as shown and described in Patent No. 1,293,021, issued February 4, 1919, to John M. Browning, but it will be understood that the invention is 'not necessarily so limited.

An automatic machine gun of this general class is frequently required to be mounted in a relatively fixed position on an airplane and fired in synchronism with the rotation of the propeller so as to fire between the propeller blades without hitting them. Various synchronizing mechanisms and trigger motors have been devised for controlling the firing of guns mounted as described and a gun embodying the present invention is adapted to be used with a synchronizing mechanism and trigger motor of known design.

In the mounting of a gun on an airplane, it is sometimes preferable to have the trigger motor engage the gun at the right side thereof and it is sometimes preferable to have it engage the gun at the left side thereof. One object of the present invention is to provide a gun so constructed that the trigger motor can be applied thereto at either side. The construction of the firing mechanism of the gun is such that by merely reversing the positions of certain parts the gun can be adapted for operation by means of a trigger motor at either side.

It is also desirable not only to be able to operate the firing mechanism from either side but also to be able to effect the feeding of the cartridge belt in either direction, that is, from left to right or from right to left. A further object of the invention, therefore, is to provide improved details of construction which facilitate the adaptation of the gun for feeding the cartridge in either direction as required.

Further objects of the invention will be apparent from the following specification and claims.

In the accompanying drawings I have shown a machine gun similar in many respects to that shown in the before mentioned Browning patent and reference can be had to that patent for such details of construction as may not be fully apparent from the present drawings and description. As concerns the parts of the gun to which the invention particularly relates, it is to be understood that the drawings are for illustrative purposes only and are not'to be construed as defining or limiting the scope of the invention, the claims forming a part of this invention being relied upon for that purpose.-

Of the drawings:

Fig. 1 is a plan view of a machine gun embodying the invention, the front end of the barrel and barrel jacket being broken away.

Fig. 2 is a side view of the parts shown in Fig. 1.

Fig.3 is a rear end view.

Fig. 4 is a perspective view ShOWiHg the Eracket for guiding the manual operating Fig. 5 is a perspective view showing a trigger motor that is interchangeable with the bracket shown in Fig. 4.

Fig. ,6 is a vertical longitudinal sectional view on an enlarged scale.

Fig. 7 is a view similar to Fig. 6 but showing the parts in different relative positions.

Fig. 8 is a fragmentary rear view on an enlarged scale of the breech bolt and parts carried thereby, this view being taken approximately along the line 8-8 of Fig. 6.

Fig. 9 is a fragmentary vertical sectional view taken along the line 99 of Fig. 8. r

Fig. 10 is a fragmentary horizontal sectional View taken along the line 10-10 of Fig. 8.

Fig. 11 is a viewsimilar to Fig. 8 but showing some of the parts in different positions.

Fig. 12 is a view similar to Fig. 10 but showing the parts in the same positions as in Fig. 11.

Fig. 13 is a perspective view of the sear.

Figs. 14 and 15 are rear and side views respectively of the sear operating lever.

Figs. 16, 17 and 18 are top, rear and side views respectively of the spring plunger device cooperating with the sear lever.

Figs. 19 and 20 are plan and side views respectively of the pin lever for holding the plunger device in place.

Fig. 21 is'a fragmentary longitudinal sectional view similar to Fig. 6, but showing a open positions.

manual firing mechanism substituted at the rear.

Fig. 22 is a rear view of the manual firing mechanism as shown in Fig. 21.

Figs. 23 and 24 are rear and side views respectively of the trigger.

Figs. and 26 are rear and side views respectively of the housing for the trigger lock.

Fig. 27 is a perspective view of the trigger lock. 4

Fig. 28 is a view showing in detail the parts of the screw and detent device forming parts of the trigger lock mechanism.

F ig. 29 is a fragmentary plan View showing the feed mechanism.

Fig. is a View similar to Fig. 29, but showing certain parts of the feed mechanism in reversed positions.

Fig. 31 is a transverse sectional view taken along the line 3131 of Fig. 29.

Fig. 32 is a transverse sectional view taken along the line 32-32 of Fig. 30.

Figs. 33, 34 and are plan, rear and right side views respectively of the feed slide.

Figs. 36 and .37 are plan and rear views respectively of the feed pawl.

Figs. 38 and 39 are plan and rear views respectively of the feed pawl extension.

Figs. and 41 are plan and side views respectively of the feed lever.

The machine gun as shown in the drawings comprises a breech casing 1 which contains the breech mechanism, this casing being rectangular in form and having two side plates 2, 2 connected at the front with a trunnion block 3. The rear part of the bottom of the casing is closed by a transverse bottom plate 4 and the rear part of the top of the casing is closed by the top plate 5. In front of the plate 5 there is also provided a cover 6 pivoted at 7 so that it can be swung upward to expose the interior parts. A spring plunger 7 engages notches in the hub of the cover.

to releasably hold it in any one of several The cover 6 is normally held closed by means of a latch at 8 operated by a finger piece 8.

The casing is closed at the rear by means of a plate 9 which is vertically movable in grooves (not shown) formed in the two side plates 2, 2. The plate 9 is held in place by a manually releasable pivoted latch 10. The plate 9 carries a buffer mechanism indicated as an entirety by 11. This buffer mechanism is not shown in detail as it constitutes no part of the present invention.

Projecting from the casing at the front is a barrel 12 which upon recoil is movable rear; ward to a limited extent. tends through a bearing aperture 13 in the trunnion block 3 and it has another hearing at or near the forward end of the barrel jacket 14, the said jacket being carried by a flange 15 formed on the trunnion block. Connected with the barrel 12 at the rear end thereof and The barrel ex eoaeaa bodily movable therewith is a barrel extension 16. This barrel extension comprises two integrally formed side members, one of which, 16, is clearly shown in Figs. 6 and 7. These two side members are connected at the rear by a recessed cross member 16".

Mounted on the barrel extension for longitudinal movement independently thereof is a breech bolt 17. This breech bolt is provided at its opposite sides with longitudinal tongues 17 ,17 adapted to enter longitudinal grooves 16 formed in the side members 16 of the barrel extension. The rear part of the breech bolt 17 is extended transversely, as clearly shown in Fig. 10 so as to occupy the entire width of the casing between the two side plates 2, 2. A reaction spring 18 is provided which extends into a longitudinal opening 19 in the breech bolt and which tends to hold the breech bolt in its forward position. Upon recoil this reaction spring is compressed and immediately tends to return the breech bolt in the forward direction.

Mounted in the rear lower part of the casing is a lock frame 20 comprising two side members lying closely adjacent the side walls 2. 2 of the casing. Immediately in front of the lock frame 20 is a transverse block 21 secured to the bottom wall .4. When the parts are in their forward positions as shown in Fig. 6 the breech bolt is locked to the barrel extension by means of a lock bolt 22 vertically movable in a recess in the transverse portion 16 of the barrel extension and entering a notch 23 in the breech bolt. The lock bolt 22 is held in its upper locking position by means of the transverse block 21, but when the barrel extension and breech bolt move rearward, the said lock bolt is moved downward by means of cam surfaces 24 formed at the forward ends of the lock frame 20. This permits the breech bolt to move rearward independently of the barrel extension as clearly shown in Fig. 7. lVhen the parts are returned to their forward positions the lock bolt 22 is again moved to locking position by means of the cam surface 25 on the block 21.

Transversely pivoted on the lock frame 20 is a rock lever or accelerator 26 having a convex forward facing surface adapted to be engaged by the rear surface of the barrel extension. When the barrel extension moves rearward upon recoil the breech bolt is unlocked therefrom in the manner already described and the accelerator 26 is moved in the counter-clockwise direction. The upper end of the accelerator engages the surface 27 on the breech bolt and the accelerator thus serves to assist or accelerate the rearward movement of the bolt, acting as a means for transmitting the energy of the relatively heavy barrel extension and barrel to the lighter breech bolt. As the breech bolt moves rearward the surface 27 is separated from the accelerator and the bottom of the breech bolt moves over the accelerator thus holding it in its rearmost position as clearly shown in Fig. 7. When the accelerator is in this position an extension 26 thereof engages an extension 16 on the barrel extension to positively hold the said barrel extension in its rearmost position until such time as the breech bolt moves forward.

Carried by the lock frame 20 is a slidable rod 28 surrounded by a coil spring 29 tend ing to move the r'od toward the front. The extension 16 on the "barrel extension abuts against the front end of the rod and the spring 29 thusv serves to resist rearward movement of the barrel extension and to assist forward movement thereof.

The breech bolt 17 has a centrallongitudinal opening therein adapted to receive the firing pin 30. The firing pin 30 is hollow having a spring 31 therein which abuts at its rear against a transverse pin extending through a slot 30 in the -firing pin. The spring 31 thus serves to bias the firing pin for movement in the forward direction. Pivotally mounted on the breech bolt is a cocking lever 32 mounted on a removable transverse pin 32. The upper end of the cocking lever extends into a suitable slot in a block 33 secured to the top wall 5 of the casing, and the lower end extends into the slot 30 in the firing pin. The cooking lever is so formed and positioned that, when the breech bolt moves rearward, the cocking lever is turned in the clockwise direction and serves to move the firing pin relatively rearward to its cocked position where it is engaged by the sear to be presently described.

Pivotally mounted on the breech bolt at the left side thereof is an extractor 34 controlled.

by a cam spring 35 and a cam rib 35 on the cover 6 and further controlled by cam plates 36 and 36 secured to the left side wall 2 of the casing. As the breech bolt'moves rearward the extractor withdraws a cartridge from the feed mechanism at the front and is moved downward by reason of engagementwith the cam 35 and 35. As the breech bolt moves forward the cartridge is moved into the firing chamber of the barrel and the extractor is returned by the cam 36. to its upper position as shown in Fig. 6 where it engages the next cartridge. Whenthe feed mechanism is reversible as is preferred and as is hereinafter described, certain portions of the extractor are also reversible but this constitutes no part of the present invention.

The movements of the barrel extension and breech bolt and other parts as described ordinarily occur automatically as the result of the recoil action of.the firearm. However, in order to test the mechanism and in order to place the first cartridge in the firing chamber, means is provided for operating .the parts manually. One of the side walls 2 of the casing is provided with a longitudinal slot 37 and preferably there is such a slot in each side wall. A pin 38 is provided which may be inserted through either slot into a suitable transverse hole in the breech bolt.

The pin 38 is held in place by a shoulder (not shown) which engages the corresponding side plate at the edges of the slot 37. The slots 37 are enlarged at the rear to'permit the removal or insertion of the pin.

As shown most clearly in Fig. 4 theside wall 2 of the casing is also provided with openings 39 and 39 adapted to receive a bracket 40. When there is a slot 37 in each side wall there are openings 39 and 39 in each side wall. The bracket 40 has a beveled surface at the front adapted to engage a similarly beveled surface at the front edge of the opening 39 and the bracket is further provided with a bolt 41 having an enlarged head with a beveled surface at the rear adapted to engage a beveled surface at the rear of the opening 39*. An inspection of Fig. 4 will show that when the bolt 41 is tightened the bracket 40 is securely fastened to the corresponding side wall of the casing. The beveled surfaces at the edges of the openings 39 and 39 thus serve as attachment means.

The bracket 40 is proyided with guide slots 40 and 40 each adapted to receive a longitudinally extending bar 42. When the bracket is at the right, as shown in Figs. 1 to 4, the bar 42 is guided in part by the said guide 40' and it is also guided in part by the corresponding one of two other brackets 43, 43 permanently secured to the casing. Each of the brackets 43 is provided with a spring plunger 43 adapted to enter a recess in the bar 42 to releasably hold the bar in its forward position. A stop 42 on the bar 42 serves to limit forward movement. The bar 42 is provided with a slot 44 through which the pin 38 extends and the said bar is provided at its rear with a suitable handle 45. It will be obvious that by pulling rearward upon the handle the pin 38 may be moved rearward thus actuating the breech bolt and causing the mechanism of the gun to operate. The length of the slot 44 is sufficient to permit the pin 38 to move automatically with- .out operating the bar 42.

As already stated the bracket 40 has two guide slots 40 and 40 and is so constructed as to be reversible. that is. it is so constructed that it can be applied to the right side of the gun or to the left side. 'The bracket can be secured to either side plate at the openings 39 and 39 therein. Then the bracket is at the right the guide slot 40 is used, and when the bracket is at the left the slot 40 is used. It will therefore be apparent that the handle 45 and theassociated parts may be located either at the right side of the gun as shown or at the left side. When they are to be placed at the left-'side, the pin 38 is with drawn and inserted at the left.- With the handle 45 and the bar 42 located at the left, the operation is exactly the same as that already described.

A firearm embodying the presentinvention is primarily intended to be fired auto? matically by means of a trigger motor actuated by a suitable synchronizing mechanism as already stated. Preferably the bracket 40 is so constructed and is of such size as to be interchangeable with the trigger motor intended to be used. Fig. 5 shows a trigger motor which is adapted 'to be mounted and held in place in the same way as already described for the bracket 40, there being provided for this purpose a bolt M similar to the bolt 41. Fig. 1 shows the trigger motor M located at the left side of the gun and the bracket 40 located at the right side of the gun, but it will be understood that in accordance with the invention the trigger motor may be located at either side and that the bracket 40 and that the parts associated therewith are located at the side opposite the trigger motor.

The trigger motor need not be fully described, but as shown in Fig. 5 the said motor comprises a transversely moving actuating member m which is adapted to operate the firing mechanism when the breech bolt is in its forward firing position. The member 772. serves to move the sear in the direction necessary to release the firing pin. Impulses are transmitted to the member m by means of a longitudinally movable plunger m actuated by a lever m. A cable or lanyard may be connected to the lever m" to transmit motion from a suitable mechanism timed with the propeller of the airplane. Thus the member on is operated in timed relation with the propeller. When the trigger motor is at the right, as shown in Fig. 5, the lanyard is connected at the top, and when the trigger motor is at the left, as shown'in Fig. 1, the lanyard is connected at the'bottom.

As shown most clearly in Figs. 8, 9 and 10 the breech bolt 17 is provided at the rear with a transverse horizontal slot or guideway in which is located a transversely and horizontally movable sear 46. The sear has a forward extending hook portion 46 which is adapted to engage a locking shoulder 3O formed on the firing pin near the rear thereof. Preferably the shoulder 80 is the rear wall of a notch cut into the pin.

'Also carried by the breech bolt adjacent the sear is a movable member 47 operatively connected with the sear and preferably having a portion which is movable vertically to effect horizontal movement of the sear. Preferably and as shown the member 47 is a rock lever or hell crank positioned in a recess 17 in the rear part of the breech bolt and movable about a longitudinal axis. This sear lever 47 is shown in detail in Figs. 14 and 15 and it is provided with a trunnion 47 adapted to enter a hole 48 formed in the breech bolt near the right side of the recess 17 The lever 47 has an elongated slot 47 adapted to receive a pin 46 projecting rearward from the sear.

Extending downward from the top of the breech bolt and at the rear thereof is a T-slot' 49 adapted to receive a combined retaining member and spring housing 50 which is shown in detail in Figs. 16, 17 and 18. When this member is in its normal position as shown in Figs. 8 and 9 2. portion'of it extends in back of the sear lever 47 thus serving to hold the said lever in place. Positioned within the member 50 is a spring pressed plunger 51 which bears against the top of the horizontal arm of the lever 47 thus tending to turn the lever in the counterclockwise direction and to thereby move the sear toward the left and into engagement with the firing pin.

The member 50 is locked in position by means of a pin lever 52' shown in detail in Figs. 19 and 20. As shown in Fig. 6 the forward pivot pin of this lever is adapted to be located in a vertical hole in the bottom of a longitudinal slot .17 c at the top of the breech bolt. 'This'pin forming a partof the lever preferably also serves as theaforesaid pin against which the spring 31 abuts at the rear. The lever 52' is recessed at 52' to' clear the cocking lever 32. v The rear part of the lever 52 extends over the top of the member 50 and when the member 50 is in its lower position the lever 52 may be swung laterally into a notch at theleft side of the slot 17 asclearly shown in Fig.8. Abeveled surface 50 at the top ofthe member 50 tends to prevent movement of the lever 52 toward the right and out of the notch. It will be understood that the cocking lever 32 must be removed before the pin lever 52 can be removed.

The sear 46 is preferably so constructed as to be reversible. It may occupy either the position shown in Figs. 8 to 10 or the position shown in Figs. 11 and 12. In this latter position the hook portion 46 of the sear no longer engages the shoulder of the firing pin but engages a similar shoulder 30 'at the left side thereof. When the sear opera-ting member 47 is a rock lever as shown and described, this lever is also reversible, so that it may be reversed when the sear is reversed. In order that the lever 47 maybe reversed it is provided with a trunnion 47 similar to the trunnion 47 and adapted to enter a hole 48 at the left of the center of the breech bolt and similar to the hole 48. The retaining member 50 occupies the same position as before and serves to hold the lever 47 in place. The spring plunger 51 engages the lever exactly as before but now tends to move it in the clockwise direction so as to move the sear toward the right and into engagement with the firing pin.

In Fig. 11 the trigger motor M is shown as located at the right side of the gun with the transversely movable member on thereof in position to directly engage the sear 46 to move it toward the left, that is, in direction to release the firing pin. If the trigger motor were located at the left, then the sear and associated parts would be in the relative positions shown in Figs. 8, 9 and 10. In operation the trigger motor is located at the right side or at the left side, and is actuated as already described in synchronism with the rotation of the propeller, with the result that the member m is rapidly reciprocated transversely. When the gun has once been fired the parts move rearward during recoil in the manner already described and then return to the forward firing position. parts reach the said forward firing position, firing takes place upon the next inward movement of the actuating member m. Ordinarily the reciprocation of the member m is.

much more rapid than the firing action of the gun, with the result that firing occurs immediately, or substantially immediately, upon the return of the breech bolt to its forward firing position.

While a firearm embodying the present invention is primarily intended to be fired automatically I nevertheless prefer to provide means whereby the gun may be fired manually. Manual firing may be desirable for purposes of testing or to enable the gun to be used as a ground gun when necessary. Pivotally mounted on the lock frame 20 is a trigger lever 53 which is so formed and so located that its forward end is immediately below and in register with the operating member or lever 47 when the breech bolt and attached parts are in their forward firing positions. The gun as shown in Figs. 6 and 7 includes no means for operating the trigger lever 53' but the said lever is provided so that it can be operated when other parts are substituted as will now be described.

In Figs. 21 and 22 I have shown an alternate rear plate 54 which may be substituted for the plate 9 already described. This plate 54 is held in place by a latch 55 similar to the'heforeinentioned latch 10. Carried by the plate 54 is a buffer mechanism 56 which serves the same purpose as the buffer mechanism 11 although differently constructed.-

Connected with the plate 54 are two spaced handles 57, 57 by means of which the gun may be moved or positioned in case it is to be used as a ground gun.

Carried by the plate 54 is a pivotally mounted trigger 58 having a finger piece 58 facing toward the rear and located between the two handles 57, 57. A forward extending arm 58 of the trigger extends through a suitable slot in the plate 54 and is positioned immediately above the rear end of the trigger lever 53. A spring 59 tends to move the trigger rearward. When the gun is to be fired After the manually the operator presses the trigger 58 forward, thus depressing the rear end of the a lever 53 and elevating the front end thereof. By reference to Figs. 8 and 9 it will be apparent that when the front end of the lever 53 moves upward the sear lever 47 is moved horizontally in the direction to release the sear from the firing pin and .thus cause the gun to be fired. It will be apparent that the action of .the trigger and trigger lever is the same irrespective of the position of the sear and sear lever. In other words, when the gun is to be operated manually it is entirely immaterial whether the sear and sear lever are located in the positions shown in Fig. 8 or in the positions shown in Fig. 11. It will further be apparent that the gun may be fired manually notwithstanding the presence thereon of a trigger motor such as M. The manual action simply moves the sear away from the trigger motor and the trigger motor does not interfere in any way with the searmovement. It will also be apparent that the gun may be fired automatically even though the plate 54 and the attached parts are in place.

I preferably provide a safety device which prevents the firing of the gun when the trigger 58 is pressed accidentally or unintentionally. Mounted on the plate 54 immediately in front of the upper part of the trigger is a block 60 having a notch 60 in the front and also having a transverse groove 60" therein for thereception of a transversely movable safety bar 61. The block 60 is held in place by means of a screw 62 extending downward from the top flange to which the handles 57, 57 are connected. Seated within this screw is a plunger 63 operated by a spring 63*, the plunger being adapted to enter one or the other of two recesses 61 in the safety bar 61. With the safety bar in the left position as shown in Fig. 22 the trigger can be'pressed, a portion of the ever, with the -bar61 in the right position as shown in Fig. 25 the notch 61 is out of register and the said bar interferes with the trigger and prevents firing movement thereof.

Extending transversely through the gun near the front thereof is a feed channel 64 into which a cartridge belt may be fed either from the left or from the right. Mounted in a downward extension of the cover 6 immediately above the feed channel 64 is a feed slide 65 which is adapted to move transversely. This slide 65 carries a pawl 66 wh1ch is adapted to engage the forward cartridge of the cartridge belt to move it into firing position as shown in Fig. 31 or in Fig. 32. The slide 65 with the pawl 66 thereon is bodily reversible so as to be adapted to feed the belt from left to right as shown in Fig. 31 or from right to left as shown in Fig. 32. The pawl 66 preferably carries an extension 67 shown in detail in Figs. 38 and 39 which is adapted to be secured thereto at the rear side thereof. When the slideand pawl are reversed as already referred to, this extension 66 is transferred from one side of the pawl to the other so that in either case it is at the rear.

At the sides of the gun are blocks 68, 68 located immediately below the feed channel and serving to form the end portions thereof. Pins 69, 69 extend longitudinally through holes in these blocks and on one of these pins there is located a pawl 70 adapted to engage one cartridge of the belt to prevent backward movement thereof. When the belt is to be fed from left to right as shown in Fig. 31 the pawl is located at the left, and when the belt is to be fed from right to left as shown in Fig. 32 the pawl is located at the right. For limiting the movement of the front cartridge of the belt there are preferably provided suitable stops 71 and 72 which are held in place by means of one of the pins 69. When the feed is from left to right the said stops are at the right and when the feed is fromright to left the said stops are at the left.

For operating the slide 65 there is provided a feed lever 73 which is pivotally mounted on a stud 74 projecting downward from the cover 6. The slide 65 is provided with two notches 7 5, 75 and the forward end of the lever 7 3 projects into one or the other of these notches according to the position of the slide. Atthe rear end of the lever 73 there is provided a depending stud 76 which extends into a cam groove 77 formed in the upper surface of the breech bolt 17 The lever 73 is provided near its pivot with a hole 78 in which is seated a spring 79 actuating a plunger 80. This plunger 80 bears against 9. depending side flange of the cover as clearly shown in Fig. 29. The spring 79, therefore, tends to move the lever in the clockwise direction and thus tends to hold the slide 65 in its extreme position toward the right. It will be obvious that when the breech bolt moves rearward the lever 73 will be moved in the counter-clockwise direction in opposition to the action of the sprin pressed plunger. The lever moves the sli e 65 far enough toward the left to enable the pawl'66 to engage the next cartridge of the belt, it being understood that in the meantime the first cartridge thereof is withdrawn by the extractor as already described. As the breech bolt again moves forward the lever 73 is rotated in the clockwise direction, thus moving the slide 65 and pawl 66 toward the right and advancing the forwardcartridge of the belt to the position shown'in Fig. 31.

When it is desired to effect feeding from right to left instead of from left to right, the feed slide and other parts are reversed as already described. The breech bolt 17 is removed and another breech bolt 17' is substituted therefor which is identical in construction therewith except that it is provided with a cam groove 77 reversed inposition with respect to the cam groove 7 7. The spring 79 and the plunger 80 are transferred from the hole 78 in the lever 73 to a similar hole 78 formed in the said lever at the other side of the-pivot. With the gun arranged for feeding from right to left the parts are positioned as shown in Figs. 30 and 32, the spring 79 tending to move the lever 73 in the counterclockwise direction so as'to hold the' slide 67 in its extreme position toward the left. The action of the feeding mechanism'is exactly the same as before except for the reversal of the directions of movement. The slide 65 is initially moved from left to right so that upon the return movement the cartridge will be fed from right to left.

What I claim is: a a

1. In an automatic firearm, the combination of a breech casing having two similar means at opposite sides thereof each adapted for the attachment of a trigger motor, a breech bolt within the casing and reciprocable upon recoil, reversible firing mechanism adapted when the breech bolt is in its forward firing position to be operated by a trigger motor attached at either side of the casing, a bracket attached to the casing by the attachment means thereof opposite to that used by the trigger motor, and means carried at least in part by the bracket for manually operating the breech bolt.

2. In an automatic firearm, the combination of a breech bolt longitudinally reciprocable upon recoil, a spring actuated firing pin movable longitudinally of the breech bolt and provided with a sear engaging shoulder at one side, a cocking lever on the breech bolt acting automatically during recoil to move the firing pin relatively rearward to cocked position, and a transversely and horizontally movable sear carried by the breech bolt and biased for movement in one direction to engage the firing pin at the shoulder thereof to hold the pin in cocked position, the saidsear being adapted to be moved in the opposite direction to release the firing pin.

3. In an automatic firearm, the combination .of a breech bolt longitudinally reciprocable upon recoil, a spring actuated firing pin movable longitudinally of the breech bolt, a cocking lever on the breech bolt acting automatically during recoil to move the firing pin relatively rearward to cocked position,-and a transversely and horizontally movable sear carried by the breech bolt and having a portion at one side of the firing pin adapted to-engage the said pin to hold it in cocked position, the said sear also having a portion at the opposite side of the firing pin adapted to be engaged for moving the sear to disengage the first said portion thereof from the pin.

4. In an automatic firearm, the combination of a breech casing having a hole in one side thereof adapted for the entry of the reciprocating actuating element of a separate trigger motor, a breech bolt within the casing and longitudinally reciprocable upon recoil, a spring actuated firing pin movable longitudinally of the breech bolt, a cocking lever on the breech bolt acting automatically during recoil to move the firing pin relatively rearward to cocked position, and a transversely and horizontally movable, sear carried by the breech bolt and biased for movement in one direction to engage the firing pin to hold it in cocked position, the said sear being in register with the said hole in the easing when the breech bolt is-in firing position and being adapted to be directly engaged by the actuating element of the trigger motor and thereby moved in the direction opposite to the first said direction to release the firing pin.

5. In an automatic firearm, the combination of a breech bolt longitudinally movable upon recoil, a spring actuated firing pin movable longitudinally of the breech bolt and provided with two sear engaging shoulders at opposite sides thereof, a cocking lever on the breechbolt acting automatically during recoil to move the firing pin relatively rearward to cocked position, a transversely movable sear carried by the breech bolt and reversible in position with respect thereto, the said scar when in one position being'adaptcd to engage the firing pin at one shoulder thereof to hold it in cocked position and when in the reversed position being adapted to similarly engage the pin at the opposite shoulder thereof, and means operable with the sear in either position for releasably maintaining it normally in engagement with the pin, the last said means permitting the sear to be moved in one direction or the other according to its position for the purpose of releasing the pin.

6. In an automatic firearm, the combination of a breech bolt longitudinally reciprocable-u'pon recoil, a spring actuated firing pin movable longitudinally of the breech bolt, a cocking lever on the breech bolt actlng automatically during recoil to move the firing pin relatively rearward to cocked position, a transversely and horizontally movable sear carried by the breech bolt and reversible in position with respect thereto, the said sear when in one position being adapted to engage the firing pin at one side thereof to hold it in cocked position and when in the reversed position being adapted to similarly engage the pin at the opposite side thereof, means operable with the sear in either position for releasably maintaining it-normally in engagement with the pin, and a breech casing enclosing the rcciprocable breech bolt and having two holes therein at opposite sides thereof each adapted for the entry of the transversely movable actuating element of a separate trigger motor, the said holes in the'casing being so located that one or the other of them according to the position of the sear is in register therewith when the breech bolt is in firing position thus enabling a trigger motor at one or the other of the said holes to directly engage the-said sear and move it in one direction or the other as required to release the firing pin.

7. In an automatic firearm, the combination of a breech bolt longitudinally reciprocable upon recoil, a spring actuated firing pin movable longitudinally of the breech bolt, a cocking lever on the breech bolt acting automatically during recoil to move the firing pin relatively rearward to cocked position, a transversely and horizontally movable sear carried by the breech bolt and biased for movement in one direction to engage the firing pin to hold it in cocked position, a relatively movable member carried by the breech bolt adjacent the sear and operatively connected therewith, and manually operable trigger mechanism for moving the last said member so as to thereby move the sear horizontally in the direction opposite to the first said direction to release the firing pin.

8. In an automatic firearm, the combination of a breech bolt longitudinally reciprocable upon recoil, a spring actuated firing pin movable longitudinally of the breech bolt, a cocking lever on the breech bolt acting automatically during recoil to move the firing pin relatively rearward to cocked position, a transversely and horizontally movable sear carried by the breech bolt and biased Bil for movement in one direction to engage the firin pin to hold it in cocked position, a relatively movable member carried by the breech bolt adjacent the sear and operatively connected therewith, and manually operable trigger mechanism for moving at least a portion of the last said member substantially vertically so as to thereby move the sear horizontally in the direction opposite to the first said direction to release the firing pin.

9. In an automatic firearm, the combination of a breech bolt longitudinally reciprocable upon recoil, aspring actuated firing pin movable longitudinally of the breech bolt, a cooking lever on the breech bolt acting automatically during recoil to move the firing pin relatively rearward to cocked position, a transversely and horizontally movable sear carried by the breech bolt and biased for movement in one direction to engage the firing pin to hold it in cocked position, a lever pivoted to the breech bolt for movement about a longitudinal axis and having operative connection with the scar, and manually operable trigger mechanism for operating the last said lever to thereby move the sear in the direction opposite to the first said direction to release the firing pin.

10. In an automatic firearm, the combination of a breech casing having a hole in one side thereof for the entry of the reciprocating actuating element of a separate trigger motor, a breech bolt within the casing and longitudinally reciprocable upon recoil, a spring actuated firing pin movable longitudi nally of the breech bolt, a cooking lever on the breech bolt acting automatically during recoil to move the firing pin relatively rearward to cocked position, a transversely and horizontally movable sear carried by the breech bolt and biased for movement in one direction to engage the firing pin to hold it in cocked position, the said sear being in register with the said hole in the casing when the breech bolt is in firing position and being adapted to be directly engaged by the actuating element of the'trigger motor and thereby moved in the direction opposite to the first said direction to release the firing pin, a relatively movable member-carried by the breech bolt adjacent the sear and operatively connected therewith, and trigger mechanism for operating the last said member to thereby move the sear independently of the trigger motor in the said opposite direction to release the firing pin.

11. In an automatic firearm, the combination of a breech bolt longitudinally movable upon recoil, a spring actuated firing pin movable longitudinally of the breech bolt and provided with two sear engaging shoulders at opposite sides thereof, a cocking lever on the breech bolt acting automatically during recoil to move the firing pin relatively rearward to cocked position, a transversely and horizontally movable sear carried by the breech bolt and reversible in position with respect thereto, the said sear when in one position being adapted to engage the firing pin at one shoulder thereof to hold it in cocked position and when in the reversed position being adapted to similarly engage the pin at the opposite shoulder thereof, means operable with the sear in either of its relatively reversed positions for releasably maintaining it normally in engagement with the pin, a relatively movable member carried by the breech bolt adjacent the sear and operatively connected therewith. in each position thereof, and manually operable trigger mechanism for operating the last said member to thereby move the sear in one horizontal direction or the other as required to release the firing pin.

12. In an automatic firearm, the combination of a breech bolt longitudinally movable upon recoil, a. spring actuated firing pin movable longitudinally of the breech bolt and provided with two sear engaging shoulders at opposite sides thereof, a cooking lever on the breech bolt acting automatically during recoil to move the firing pin relatively rearward to cocked position, a transversely movable sear carried by the breech bolt and reversible in position with respect thereto, the said sear when in one position being adapted to engage the firing pin at one shoulder thereof to hold it in cocked position and when in the reversed position being adapted to similarly engage the pin at the opposite shoulder thereof, means operable with the sear in either of its relatively reversed positions for releasably maintaining it normally in engagement with the pin, a lever pivoted to the breech bolt for movement about a longitudinal axis, the said lever being reversible in accordance with the position of the scar and having operative connection with the sear in each position thereof, and manually operable trigger -mechanism for operating'the last said lever in either of its relatively reversed positions to thereby move the sear in one direction or the other as required to release the firing pin.

13. In an automatic firearm, the combination of a breech bolt longitudinally reciprocable uponrecoil, a spring actuated firing pin movable longitudinally of the breech bolt, a cooking lever on the breech bolt acting automatically during recoil to move the firing pin relatively rearward to cocked position, a transversely and horizontally movable sear carried by the breech bolt and reversible in position with respect thereto, the said sear when in one position being adapted to engage the firing pin at one side thereof to hold it in cocked position and when in the reversed position being adapted to similarly engage the pin at the opposite side thereof, means operable with the sear in either of its relatively reversed positions for releasably maintaining it normally in engagement with the pin, a breech casing enclosing the reciprocable breech bolt and having two holes therein at opposite sides thereof each adapted for the entry of the transversely movable actuating element of a separate trigger motor, the said holes in the casing being so located that one or the other of them according to the position of the sear is in register therewith when the breech bolt is in firing position thus enabling a trigger motor at one or the other of the said holes to directly engage the said sear and move it in one direction or the other to release the firing pin, a relatively movable member carried by the breech bolt adjacent the sear and operatively connected therewith in each position thereof, and manually operable trigger mechanism for operating the last said member to thereby move the sear independently of the trigger motor in one horizontal direction or the other as required to release the firing pin.

14. In an automatic firearm, the combination of a breech bolt longitudinally reciprocable upon recoil, a spring actuated firing pin movable longitudinally of the breech bolt, a cooking lever on the breech bolt acting automatically during recoil to move the firing pin relatively rearward to cocked position, a lever pivoted to the breech bolt for movement about a longitudinal axis, a spring serving to bias the lever for movement in one direction, and a transversel and horizontally movable sear carried by t e breech bolt and operatively connected with the last said lever to be thereby biased for movement in the direction to engage the firing pin and hold it in cocked position, the said sear being adapted ,to be moved in the opposite direction to release the firing 1n. p 15. In an automatic firearm, the combination of a breech boltlongitudinally reciprocable upon recoil,'a spring actuated firing pin movable longitudinally of the breech bolt, a cooking lever on the breech bolt acting automatically during recoil to move the firing pin relatively rearward to cocked position, a removable lever pivoted to the breech bolt for movement about a longitudinal axis, a sear carried by the breech bolt and transversely movable in one direction to engage the firing pin to hold it in cocked position, the said sear bein operatively connected with the last said fiver and being adapted to be engaged independently of the lever and moved in the direction opposite to the first said direction to release the firing pin,v a spring housing detachably mounted on the breech bolt and serving when in normal position to retain the last said lever and prevent removal thereof, and a spring carried by the housing and serving tobias the leverin the direction to move the sear into engagement with the firing pin.

16. In an automatic firearm, the combination of a breech bolt longitudinally recipro cable upon recoil, a spring actuated firing pin movable longitudinally of the breech bolt, a cockin lever on the breech bolt acting automatica ly during recoil to move the firing pin relatively rearward to cocked position, a lever pivoted to the breech bolt for movement about a longitudinal axis, a spring engaging the lever to bias it in one direction, a sear carried by the breech bolt and transversely movable in one direction to engage the firing pin to hold it in cocked position, the said sear being operatively connected with the last said lever to be thereby biased for movementin the first said direction and being adapted to be directly engaged independently of the lever and moved in the opposite direction to release the firing pin, and manually operable trigger mechanism for operating the lever to thereby move the sear in the last said opposite direction to release the firing pin.

17 In an automatic firearm, the combination of a breech bolt longitudinally movable upon recoil, a spring actuated firing pin movable longitudinally of the breech bolt and provided with two sear engaging shoulders at opposite sides thereof, a cooking lever on the breech bolt acting'automatically during recoil to move the firing pin relatively rearward to cocked position, a transversely movable sear carried by the breech bolt and reversible in position with respect thereto, the said sear when in one position being adapted to engage the firing pin at one shoulder thereof to hold it in cocked position and when in the reversed position being adapted to similarly engage the pin at the opposite shoulder thereof, a lever pivoted to the breech bolt for movement about a longitudinal axis, the said lever being reversible in accordance with the position of the sear and having operative connection with the sear in each position, and a spring serving in either of the relatively reversed positions of the lever to bias it in one direction or the other as required to maintain the sear in engagement with the firing pin.

18. In an automatic firearm, the combination of a breech bolt longitudinally movable upon recoil, a spring actuated firing pin movable longitudinally of the breech bolt and provided with two sear engaging shoulders at opposite sides thereof, a cockin lever on the breech bolt acting automatically during recoil to movethe firing pin relatively rearward to cocked position, a transversely movable sear carried by the breech bolt and reversible in position with respect thereto, the said sear when in one position being adapted to engage the firing pin at one shoulder thereof to hold it in cocked position and when in retain the last said lever in either of its relatively reversed positions and prevent removal thereof, anda spring carried by the housing and serving in either of the relatively reversed positions of the lever to bias it in one direction or the other as required to maintain the sear in engagement with the firing pin.

19. In an automatic firearm, the combination of a breech bolt longitudinally movable upon recoil, a spring actuated firing pin movable longitudinally of the breech bolt and provided with two sear engaging shoulders at opposite sides thereof, a cocking lever on the breech bolt acting automatically during recoil to move the firing pin relatively rearward to cocked position, a transversely movable sear carried by the breech bolt and reversible in position with respect thereto, the said sear when in one position being adapted to engage the firing pin at one shoulder thereof to hold it in cocked position and when in the reversed position being adapted to similarly engage the pin at the opposite shoulder thereof, a lever pivoted to the breech bolt for movement about a longitudinal axis, the said lever being reversible in accordance with the position of the sear and having operative connection with the sear in each position, a spring serving in either of the relatively reversed positions of the lever to bias it in one direction or the other as required to maintain the sear in engagement with the cording to the position of the slide to feed av cartridge belt from left to right or from right to left, reciprocable breech mechanism in the casing, a feed lever pivoted to the easing for movement about a vertical axis and operatively connectible at the front to the feed slide with the latter in either of its relatively reversed positions, means carried by the breech mechanism and serving upon recoil movement thereof to turn the lever in one direction or the other to move the slide either toward the left or toward the right as required by the position thereof, and a spring reversible in its action so as to bias the lever in one direction or the other as required. I Y

21. In an automatic firearm, the combination of a breech casing having a transverse feed channel therethrough near'the front, a transversely movable feed slide reversible in position, a pawl on the slide serving accord ing to the position of the slide to feed a cartridge belt from left to right or from right to left, reciprocable breech mechanism in the casing, a feed lever pivoted to the casing for movement about a vertical axis and operatively connectible at the front to the feed slide with the latter in either of its relatively reversed positions, means carried by the breech mechanism and serving upon recoil movement thereof to turn the lever in one direction or the other to move the slide either toward the left or toward the right as required by the position thereof, and a spring on the lever adapted to be located either at the front or at the rear of the axis thereof so as to bias the lever in one direction or the other as required.

22. In an automatic firearm, the combination of a breech bolt longitudinally reciprocable upon recoil, a spring actuated firing pin movable longitudinally of the breech bolt, a

cocking lever on the breech bolt acting automatically during recoil to move the firing pin relatively rearward to cocked position, a sear carried by the breech bolt and biased for movement in one direction to engage the firing pin to hold it in cocked position, manually operable trigger mechanism for moving the sear in the direction to release-the firing pin, the said mechanism including a trigger at the rear of the firearm movable in the forward direction to release the sear, a transversely grooved block immediately in front of the trigger and having a notch for receiving a portion thereof, and a safety bar slidable in the groove in the block and having a notch movable into and out of register with the notch in the block, the said bar thus serving according to its position to permit or prevent operative movement of the trigger.

In testimony whereof I have hereunto set my hand this 13th day of November, 1929. CHRISTIAN PFEIFFE R. 

